Do the following in Linux

$1.$ Check the permission of files A$1.$sh and A$2.$sh & change the us permission to execute mode.

$2.$ Create $5$ file A$3,$ A$4,$ A$5,$ A$6,$ A$7$ in the directory ABC at once command.

$3.$ Create a group mygroup$1$ and add user by myuser$1,$ myuser$2,$ myuser$3$ in it$.$

$4.$ Change the password policy for myuser$1$ to require a new password every $90$ days.

$5$ Show the permission of above group mygroup$1.$

$6.$ What is the use of date command?